Highly acquisitive advertising giant WPP is to move its headquarters back to the UK having moved to the Republic of Ireland in 2008 to escape Britain's taxes on overseas profits earned by multi-nationals.The decision was announced with the group's interim results which saw like-for-like (LFL) revenue up 3.6% year-on-year and headline profit before tax rise by almost 12%, and more than 17% in constant currency terms, to £570m. However, the group's LFL revenue growth in July slowed, bringing LFL revenue growth in the first seven months of 2012 down to 3.5%.JH